The invention relates to a hair removing device comprising a hair removing member for removing hairs from skin, and an auxiliary member for generating a change in temperature of the skin present, during operation, near the hair removing member.
The invention also relates to an auxiliary member which can suitably be used in a hair removing device in accordance with the invention.
A hair removing device and an auxiliary member of the types mentioned in the opening paragraphs are known from WO-A-00/76363. The known hair removing device is an epilation device by means of which hairs are mechanically extracted from the skin. The hair removing member of the known hair removing device comprises a series of clamping discs which are rotatably journaled in an epilation head. During rotation of the clamping discs, said clamping discs are tiltable in pairs from a hair catching position, in which hair catching spaces are present between the pairs of clamping discs, to a clamping position in which the pairs of clamping discs are clamped against each other near their edges. Hairs that penetrate said hair catching spaces when the clamping discs are in the hair catching positions are subsequently clamped, in the clamping positions of the clamping discs, between said clamping discs and extracted from the skin under the influence of the rotating movement of the clamping discs.
The auxiliary member used in the known hair removing device is a cooling member which is provided with a skin contact element and a holder which is in thermal contact therewith, in which holder a substance having a comparatively high cold capacity is provided. The cooling member is detachably coupled to a main housing of the hair removing device. Before using the hair removing device, said substance should be cooled to a comparatively low temperature by placing the cooling member, for example, in a refrigerator for some time. If the cooling member is coupled to the main housing, the skin contact element is situated, viewed in a direction wherein the hair removing device is to be displaced over the skin, directly in front of the hair removing member. Consequently, during displacing the hair removing device over the skin, the skin is first cooled by the cooling member and immediately after that treated by the hair removing member. By previously cooling the skin, the pain that is usually felt when hairs are extracted is masked. This masking effect can be attributed to the fact that the pain stimuli generated during extracting the hairs by pain receptors present around the hairs, are only partially passed on via the nervous system because said nervous system is partly blocked to pain stimuli by the cold stimuli already present in the nervous system that are generated by the cold receptors present around the hairs. By virtue of this masking effect, the extraction of hairs is experienced as considerably less painful.
It is an object of the invention to provide a hair removing device of the type mentioned in the opening paragraph, by means of which said masking effect is enhanced, so that the pain felt during extracting hairs is reduced still further.
To achieve this object, a hair removing device in accordance with the invention is characterized in that the auxiliary member includes a heating member for generating an increase in temperature of the skin present, in operation, near the hair removing member. It has been found that the heat receptors present in the skin generate more heat stimuli per unit of time in a certain range of the skin temperature than the number of cold stimuli that can be maximally generated per unit of time by the cold receptors present in the skin. Said range of the skin temperature lies between approximately 40xc2x0 C. and 47xc2x0 C., a maximum number of heat stimuli per unit of time being generated at a skin temperature of approximately 45xc2x0 C. It is to be noted that the above-mentioned skin temperature values are values at approximately 0.1 mm below the skin surface, i.e. at the location of the heat receptors. It has been found that said larger number of heat stimuli in said range of the skin temperature leads to an increased blocking of the nervous system to the pain stimuli generated by the pain receptors during the extraction of hairs. By increasing the temperature of the skin present near the hair removing member, before extracting the hairs, by means of the heating member to a value in the above-mentioned range, an increased masking effect is achieved by means of the hair removing device in accordance with the invention, as a result of which the pain experienced during the extraction of the hairs is reduced still further.
A particular embodiment of a hair removing device in accordance with the invention is characterized in that the heating member is provided with a holder wherein a compound having a eutectic composition is provided, and a skin contact element which is in thermal contact with said compound. Such a compound crystallizes at a substantially constant temperature, the so-termed eutectic temperature, from the liquid phase to the solid phase. In this particular embodiment, the compound must be converted to the liquid phase by heating before using the hair removing device. During operation of the hair removing device, the compound crystallizes, upon reaching the eutectic temperature, from the liquid phase to the solid phase, which process takes some time as a result of the so-termed latent thermal capacity of the compound. As a result, the skin contact element is kept at a substantially constant temperature for some time, which temperature is determined by the eutectic temperature of the compound. As a result, the temperature of the skin present near the hair removing member is increased for some time by the heating member in a predetermined manner, so that said heating member provides a predetermined, desirable masking effect for some period of time. In this embodiment, the heating member has a simple structure and does not require any electrical power supply during operation of the hair removing device.
A further embodiment of a hair removing device in accordance with the invention is characterized in that the compound comprises CH3COONaxc2x73H2O or NaOHxc2x7H2O. The eutectic temperature of said compounds is 58xc2x0 C. and 61xc2x0 C., respectively. If the contact with the skin contact element is of short duration, then such temperatures of the skin contact element are not experienced as unpleasant by the user, and, if the size of the skin contact element is sufficient, the skin temperature is raised to the desired value in the range between 40xc2x0 C. and 47xc2x0 C. in a comparatively short period of time, enabling the hair removing device to be moved over the skin comparatively rapidly. Said compounds additionally have a comparatively large latent heat capacity, so that the eutectic temperatures are maintained for a comparatively long period of time and the heating member provides the desired masking effect for a relatively long period of time.
Yet another embodiment of a hair removing device in accordance with the invention is characterized in that the heating member comprises a coupling member by means of which the heating member is detachably coupled to a housing of the hair removing device. In this embodiment, before using the hair removing device, the heating member is uncoupled from said housing in order to be heated separate from the housing and the hair removing member. The uncoupled heating member can be heated, for example, in hot water or in an electrical heating apparatus. By virtue thereof, the hair removing device can be used in a very practical way.
A particular embodiment of a hair removing device in accordance with the invention is characterized in that the heating member is provided with a controllable electric resistor, a skin contact element that is in thermal contact with the resistor, and a control member for controlling the temperature of the skin contact element. In this embodiment, the heating member is embodied so as to be comparatively inexpensive, and the heating member operates in a reliable manner. In addition, the desired masking effect is continuously provided by the heating member.
A further embodiment of a hair removing device in accordance with the invention is characterized in that, in operation, the control member causes the skin contact element to be at a substantially constant temperature in the range between approximately 55xc2x0 C. and 85xc2x0 C. If the contact with the skin contact element is of short duration, then a temperature of the skin contact element in said range is not experienced as unpleasant by the user. If the size of the skin contact element is sufficient, then, at such a temperature of the skin contact element, in addition, the skin temperature is raised to the desired value in the range between 40xc2x0 C. and 47xc2x0 C. in a comparatively short period of time, enabling the hair removing device to be moved over the skin comparatively rapidly.
Yet another embodiment of a hair removing device in accordance with the invention is characterized in that the temperature of the skin contact element ranges, in operation, between approximately 77xc2x0 C. and 83xc2x0 C. At a temperature of the skin contact element in said range, the size of the surface of the skin contact element, which is necessary to enable sufficient heat to be transferred from the heating member to the skin, is limited considerably, so that the dimensions of the heating member are also limited considerably.
A particular embodiment of a hair removing device in accordance with the invention is characterized in that the heating member comprises a source of infrared light. In this embodiment, the source of infrared light is situated, in operation, at some distance from the skin. By employing said source, the skin is heated very effectively, so that the skin temperature is raised to the desired value in the range between 40xc2x0 C. and 47xc2x0 C. within a very short period of time. In addition, the heating member in this embodiment is embodied so as to be very inexpensive.